Cover for strain insulators



A. O. AUSTiN COVER FOR STRAIN INSULATORS Filed Nov. 14, 1919 PatentedJune 10, 1924.

UNITED STATES PATENT OFFICE.

ARTHUR O. AUSTIN, OF BARBER/TON, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS,TO THE OHIO BRASS COMPANY, OF MANSFIELD, OHIO, CORPORATION OF NEWJERSEY.

Application filed November 14, 1919. Serial No. 338,012. g i "I To allwhom it may concern:

Be it known that I, ARTHUR O. AUSTIN, a citizen of the United States,residing at Barberton, in the county of Summit and State of Ohio, haveinvented certain new and useful Improvements in a Cover for StrainInsulators, of which the following is a specitication.

This invention relates to strain insulators and the provision of meansfor protecting the insulators from leakage due to certain weatherconditions, particularly to water on the surface of the insulator. Theprincipal object of the invention is, therefore, to provide an insulatorwith a protecting shell either of metal or some non-conducting material.

The invention consists in the novel construction, combination andarrangement of the parts.

In the accompanying drawing- Fig. 1 is a side elevation of a cover inwhich an insulator is shown in broken out line with strain membersattached thereto.

Fig. 2 is an end view. I

Fig. 3 is an end view of a modified form of insulator; and

Fig. 4 is an end view similar to Fig. 2 showing a cover supported at adistance from the insulator by a spacing member.

In a. strain insulator it is common to separate the guy wires orconducting members by a partition of the insulating material and tospace the conducting members apartby vanes which provide a leakagesurface of considerable extent to increase the leakage path between theseparated members, there by preventing a flashoveigexcept when subjectedto high potential, or when the resistance of the leakage path is brokendown. In practice it may be that an insulator of this kind is sopositioned that some electrical conducting liquid, such as water. coversthe vanes in such a manner as to materially reduce the resistance of theleakage path between the strain members so that a flashover will occurat a much lower potential difference than is intended. The presentinvention is for the purpose of minimizing this danger to as great anextent as possible without adding to the size of the insulator itself byprotecting the surface of the insulator.

An insulator 1 of the type shown in Figs. 1 and 2 has four radiatingvanes 2 at right angles to each other, and is formed with holes 3 alsoat right angles to each other and separated by the vanes 2. Throughthese holes 3 any suitable guy wires or strain members t are loopedthrough each other so that they are separated by a par tition in theinsulator, and in the form shown these strain members are provided withheaded extremities 5, which are en gaged by socketed members 6, whichhave inside openings 7 for admitting the headed extremities 5 to holdthe strain members in place when the extremities are compressed so thatthe heads will be engaged in the sockets. To each member 6, a cable 8 isat tached in any well-known manner.

A cover 9 is applied to the insulator only, and is preferablycylindrical in form, fitting closely over the insulator with beadedportions 10 at the ends of the insulator to hold the cover in positionthereon, the cover extending some distance beyond the beaded portionand, therefore, beyond the ends of the insulator, but usuallyterminating at some distance from the socketed members 6, in which thestrain members 4 are held. This shell may be of any desirable orsuitable material, it is contemplated that it may be made of thin sheetmetal, but it may also be of some insulating material, it beingnecessary to use some material which will protect the insulator againstwater, or any other substance for which protection is needed. Thematerial of the cover may be either a conductor or a non-conductor asthe leakage path of the insulator is usually suflicient to afford thenecessary resistance if the resist ance of the path is not materiallycutdown.

As shown in Fig. 3, the same kind of a cover can be employed with aninsulator 11 of different shape in which there are a great many morevanes or fins than shown in Fig. 2, the object of which is to increasethe leakage path between the strain members. In both types of insulatorsthe cover is supported by the extremities of the vanes, and the vanesthemselves are uniform length, but it is obvious, of course, that acover of this kind might be applied to an irregularly formed insulatorin which some of the vanes were not of sufiicient length to engage thecover, and in fact the cover might be su ported entirely free fromcontact with t e extremities of the vanes by means of spacing members12, as indicated in Fig.- 4;

As this cover is preferably made of sheet metal eor otherxsheetmaterial, it may either be wrapped around the insulator and the endsfastenechor it may be made up in 1101- low or cylindrical form andpressed on or sprung in place about aninsulator where it will be held inplace by its own resiliency, as

well as by the beaded grooves 10.

It will be apparent that the shortestsurface leakage path between theconductors will be over one of the ribs 2 at points-along the insulatorwhere the conductors are in overlapping position. The points of contactbetween the cover 9 and the ribs 2 are equidistant from the separateconductors and since thesurtace of the insulator is substantiallyuniform in resistance the drop of potential to the conductors from anypoint of contact between the cover and the insulator.

2. The combination of a strain insulator having extending vanes with theouter edges all parallel and strain members separated thereby but loopedthrough each other and extending in opposite directions; and acylindrical metallic cover fitting tightly over the edges of the vanesand extending beyond the ends thereof but with inwardly grooved portionsadjacent the ends for engaging the ends/of the vanes and holdin thecover in 2:, 7

place. V

3. 'A strain insulator having a pair of conduct ngstrain members loopedthrough each other and an insulating member with a partition spacing theloopedportions apart and with extending vanes forming a leakage pathbetween the strain members, and a me tallic cover supported by the outeredges of the vanes to protectthe insulator, said cover coinciding withany single leakage path at a single supporting position only. 7

4. A cover for a strain insulator comprising a cylindrical metal memberfitting over an insulator and contacting therewith at peripherallyspaced positions, the intermediate portions of said member being curvedaway from contact with said insulator with inwardly extending annulargrooves near the end to hold the member in place on an insulator.

5. A strain insulator having extending vanes, and a protecting cover ofsheet metal forming a closed-figure the interior of which engages saidvanes at peripherally spaced positions with curved intermediate portionsfree from contact with said insulator which portions can be sprung topermit the cover to be slipped on and off said insulatorover the vanesand held in place by its own resiliency.

6. A strain insulator comprising a dielectric member, interlinkedload-supporting members insulated from one another by said dielectricmember, said dielectric member having vanes extending from the bodythereof and interposed between said loads,up porting members to provideresistancelbetween said load-supporting members, and a protecting shieldof conducting material carried directly by the dielectric'member andsupported thereon at substantially equipotential points. l

7. he combination with an insulator of fragile dielectric materialhaving longitudinally extending'radial flangesthereon and supportingmembers of conducting material disposed in said flanges, 01 a protectingcover for said insulator of resilient: metal supported directly bytheoutermost edges of said flanges and bowed outwardly between the linesof support on said flanges.

In testimony whereof I have signed my name to this'specification on this'3 1st day of;

Qctober A. D. 1919.

v ARTHUR OLAUSTIN,

